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在电子工作者的电路实践中,常常需要选择特性(主要是输出特性)尽可能接近的配对晶体管,下面介绍的方法,能在同一坐标上同时显示两晶体管的输出特性,根据两管曲线的重合程度就可迅速判断两管的对称性,达到迅速准确选择配对管的目的。原理方框图如图1。T_1、T_2是被测管。B是变压器,它将交流电源按需要进行升降,次级抽头对称以便用作被测管的V_(ce)。D_1、D_2是整流管。R_c是两管集电极电压采样电阻,R_d是两管I_c采样电阻(R_c》R_d)。R_(b1)、R_(b2)用以决定被测管I_b的大小,这时取R_(b1)=R_(b2),它远大于被测管的r_(be)。CRT是示波管。工作原理如下。
In the electronic circuit practice, often need to select the characteristics (mainly the output characteristics) as close as possible pairing transistor, the method described below, the same coordinates can simultaneously display the output characteristics of the two transistors, according to the coincidence of two curves Degree can quickly determine the symmetry of the two tubes, to achieve the purpose of rapid and accurate selection of matching tube. Principle block diagram shown in Figure 1. T_1, T_2 is the measured tube. B is a transformer that raises and lowers the AC supply as needed, with the secondary tap symmetrically used as the V ce (ce) for the tube under test. D_1, D_2 are rectifiers. R_c is the two collector voltage sampling resistor, R_d is two I_c sampling resistor (R_c "R_d). R_ (b1), R_ (b2) is used to determine the size of the IUB to be measured. In this case, R_ (b1) = R_ (b2) is taken, which is much larger than r be (be) CRT is a CRT. The working principle is as follows.